Engine cylinder and method of making same



Jane 9, 1925.

T. P. GREENHOW ENGINE CYLINDER AND METHOD 0F MAKING SAME Filed May 5l, 1922 Patented June 9A, 1925.

stares 1,541,115 rarest; crei-cs.

THGMAS P. GREENEGJ, DE FLKNT, R'HCEGAN; ANDRE GRE-ENHOW' ADMINISTRA- TRX OF .SAD THDVAS E. GREENHT-N,

DECEASED.

ENGNIE CYTINDER AND METHOD GF MAKNG SAME.

To @ZZ I'Lc/mm 25' may concern it known tha-t l, THOMAS P GnnnN- new, a citizen of the Uni-,ted States, residing at Flint, in the county of Genesee and State of Michigan, have invented certain new and useful improvements in Engine Cylinders and liiethods of Makin-g' Same, of which the following is a speciiication.

My invention relates to foundry practice and more particnilarlyv to cast metal engine cylinders and the method and means for producing them.

rlhe invention .pertains to the production of engine cylinders by the use of a. chill core, whereby the interior surfaces of the cylinder barrel are rendered of uniform degree of hardness, durable and wear resistant, of increased and uniform density, free from sand vor dirt and of approximately the .Finished size, when taken from the mold, thereby econornizing in materials, and the labor and expense kof the machine operations as well as improving the wearing quality.

Engine cylinders, particularly those embodying an integral water jacket or other projections and other irregularities involving unequal distribution of the mass of metal usually possess comparatively soft interior walls subject to rapid wear and easily scored. Such cylinders frequently lack proper density and possess porous or Vspongy spots, resulting from ununiform crystallization and resulting in pore leaks. These conditions are to a very great extent due to the annealing` .effect of the surrounding water aclret wall, which is cast integral with the cylinder body, and to enlargements or vother unequal distribution of the mass of metal, which tends to retain heat and retard the cooling of the casting, thereby causing it to cool unevenly, resulting in ununiform character of the finished product. Under the usual practice, cylinder barrels vary in hardness throughout their extent being of very much softer character, under the water jacket at the very Zone where :they should be hard in order to Vafford long wearing *qualities and general durability.

The object of the present invention is to simplify the means and mode of operation of casting cylinder blocks whereby they will not only be cheapened in construction, but will be morev efficient in character, of uniform density, and uniform degree of hardness. Y

Application filed May 131,

19%2. Serial No. 564,977.

A further object of the invention is to provide means and methods .for producing` cylinder cores in close approximation to the finished si'lie and free from sand and dirt, thereby not only economizing metal, but also reducing the machining and iinishing operations to a minimum, These results are accomplished by counteracting. the annealing ei'iect of the unequal distribution .of the metal mass, in the surrounding water jacket and various projections and enlargements by chilling or .cooling .the cylinder .block from the interior, by the means .of

ychill core, the chilling capacity ofy which throughout its extent is .proportioned conversely to the heat retaining `capacity ofthe casting'. l i Y A further object of .the invention .is lto prcvide an improved form' ofy cylinder chill core, wherein the .chills are so positioned and arranged as .to compensate for contraction of the casting and to be .easily land read.- ily removable .from the finished product.

Vith the above prima-ry ,and other incidental objects in view as will more fully appear .in the specification, the invention .consists of the features of construction, .the parts and combinations thereof, fand .the mode of operation `or ltheir equivalents as hereinafter described and set forth in Athe claims.

Referring to vthe accompanying drawings, wherein is illustrated the preferred, but .ob-

viously not necessarily the yonly modefof carrying out the invention, Fig. 1 is a vertical sectional view of `a single engine kcylinder embedded in the sand mold with Athe chill core, hereinafter' described, positioned therein, illustrating in a simple manner, .the mode of carrying out the .present invention. Fig. 2 is a :transverse sectional view fof .the cylinder casting Kembedded in the mold lon line @d2 loi Fig. l. Fig. .3 isa perspective view of a portion of one half of a corefbox, with two of the segmental chill plates vpositioned therein, preparatoryvto making the cylinder core. Fig. Ll is a perspective view of one of the chill plates, separated from the core.

Like parts are indicates by ksimilar charact-ers of reference throughout the l several views.v

While engine cylinders are usually lcast in multiple wherein the rcylinder block `contains la plurality of barrels. f In ythe present instance, for illustrative purposes and te simplify therdisclosure, only a single cylinder has been shown in the. drawings. It is to be understood, however, that the` invention is equally applicabile to cylinder blocks containing Vany desired number of barrels. In the drawings, l is the engine cylinder casting of which 2 is the water jacket wall. The casting is shown of irregular shape, illustrating the ununiform distribution ot the mass of metal and consequent unequal heat retaining capacity. T his results in the annealing eect oi' certain parts of the casting, particularly those. parts beneath the surrounding water jacket wall 2, and in close proximity to exterior projections or enlargements of the metal mass. The Ycylinder casting has been shown in Figs. l Vand QI as embedded within the usual sand mold and containing a core 4. The coring o'tl castings, by casting the metal around a preformed core or interior mold oit' sand or art. Likewise the use of chills, comprising bodies of metal embedded in either the ex- VYterior or interior mold are well known.

However, there are conditions met with in the casting of hollow cylindrical bodies, such as engine cylinders and the like, and problems encountered for which Vthe customary use of chillsaftords no solution. lt has long been the practice heretofore to cast such cylinder blocks about an ordinary sand core.V Such cylinders are often found 'trom thirty-tive to sixtyper cent softer beneath the surrounding water jacket wall than elsewhere in the cylinder, due to the annealing eii'ect, of the larger mass of metal. This softness occurs throughout the particular portion of the cylinder traversed by the piston which for practical purposes should be the most hard and wear resistant. The unequal distribution oi the metal mass vfurther induces lack of density or porosity, in. this particular area of the cylinder barrel, where from a practical standpoint the metal should be most dense and without leakage. By embedding seO'mental chill plates 5 in the periphery of the core 4f, the metal torming the interior walls of the cylinder barrel coming in contact with such metal chills is quickly cooled, producing a dense hardened stratum 6, which forms a wear resistant, durable and comparatively smooth interior surface within the bore oit the casting. The use of such chill plates also enables the cylinder block to be cast more nearly to the finished dimension of the barre-l or core, thereby reducing to minimum the machining and finishing operation. In order to compensate for variations of the mass of metal comprising the casting, the chill plates 5 are varied in thickness throughout their extent. This variation et thickness may be distributed ununiformly in accordance with the ununiform distribution of metal in the casting. For illustrative purposes, the :segmental chill plates 5 have' been shown with an orl'set or shoulder 7 at a medial point whereby the upper portion ot the chill plate which will be positioned beneath the walls of the water jacket are ot greater thickness than those portions of the plate which project below the level of the jacket. It is to be understood that the chill may be made with a number of theseo'li'sets or variations of thickness or it might. be tapered uniformly from one end Yto the other, to compensate for distribution of the metal in the casting. Likewise in the event that the casting contained a considerable body of metal concentrated at one point, the chill might also.y be of increased thickness over a comparatively Vsmall localized area. Y Y

.'lheV jacketed portion of the cylinder is subjected to suiiiciently greater cooling eitfect to approximately offset the heat retaining characteristics of the unjacketed portion.- The real effect is the same whether only the jacketed portion of the cylinder is subjected to the cooling effect and the unjacketed portion not.V cooled at all, or as an alternative, the jacketed portion is subjected to a considerable degree of cooling eiect, and the unjacketed portion to a cooling effect of less degree. By proportioning the cooling eiect somewhat in relation to the heat retaining eli'ect of the jacket, a cylinder will not be unduly sott under the jacketed portion.

'llo compensate for contraction oi" the casting and to enable the chill plate 5 to be are readily removed from the barrel, they spaced apart a slight distance, leaving intern'iediate the successive segn'iental chill plates a narrow ridge 7 ot' core sand. In practice this spacing ol the chill plates one from the other is approximately three sixteenths of an inch. lflowever, this spacing may be varied by locating the chill plates closer or farther apart according to the size of the casting, and the character of the metal, and its factor ot shrinkage. ln order to locate the chill plate in properly spaced relation `for embedding in the core 4.-, the plates 'are provided with arcuate niarginal notches 8, which engage locating pins 9 .in the bottom of the. halves of the core box il). The pins 9 project from the bottom o1c the core box and receive the notches 8 of the chill plates on opposite sides. These chill plate notches are not semi-circular, but only approximately one third of a complete circle, so that the margins of the plates are separated, the requisitel distance, when the notches are fitted to the locating pins 9. These pins by their engagement in the notches also serve to locate the plates in re- 'latioiizto the-ir longitudinal adjustment. For said chill prlates,'and removing 'the cast cylconvenience ,of vthe core maker, `and to avoid necessity o'f unnecessary handling and reversal ot' the plate, the marginal notches are provided in bot-h edges ot' the chill plate although those `in one edge only lare used Vin locating the plate in the vrespective halves ot the core -bor; l0. For instance in Fig. 3 the righ-t and lett Yplate may be interchanged by employing the locating Vnotches 8 inthe opposite margins-ot' the plate. The locating pins 9 will leave depressions or holes in the core upon its removal from the core box l0. These holes are then closed by being fillet with sand ,or other .green core material.

To aii'ord anchorage 'for the chill plaites'in lthe core a, the interior tace ot the `plates may be formed With -a number ot depressions or holes as at l1, into which the sand or core material is rammed diuingvthe core making operation7 thereby securely anchoring the chill plates upon the core body. In addition the core plates are preferably formed with slight drat or taper which further assists in holding the chill plates in place and prevent them trom. leaving the core ivhile being handled.

From the. above description it will be apparent that there is thus provided a device ot' the character described possessing the particular features of advantage before enumerated as desirable, but which obviously is susceptible ot modilication in its form7 proportions, detail construction and arrangement et parts without departing from the principle involved or sacrificing any of its advantages.

1While in order to comply with the statute. the invention has been described in language n' 'ire or less specific to structural tea- 'tuies it is to be understood that the invention Iis not limited to the specific details shown, but that the means and construction herein disclosed comprises the preferred form ot several modes o'l putting the invention into effect and the invention is theretore claimed in any of its Vforms or modifica.- tions Within the legitimate and valid scope ot the appended claims.

l-laving thus described my invention7 I claim:

l. The herein described method ot producing cast metal engine cylinders and the like consisting in Jforming a suitable core, embedding in the periphery ot' such core a plurality of segmental chill plates continuous in longitudinal direction from one end ot the area to be chilled to the other7 and spaced circumferentially one from the other, and ioining longitudinally disposed ridges of core material intermediate said chill plate, and separating them one from the other, po-A sitioning said core in a suitable mold and casting the cylinder from molten metal Within said mold and around the core containing inde-r :trom the mold and the core and chill plates from 'the cylinder.

lhe herein described method oit producing -ast metal engine cylinders and the line consisting in forming a suitable corel cnibedth-ng in the periphery .of such core a plurality of non-interengaging segmental lchill plates in separater spaced relation 'by interposed ridges ot' core material 'extending substantially flush with the faces of sai-Ld chi-ll plate to permit the contraction of the cylinder therea'bout, positioningl said core iu a suitable mold and casting the cylinder from molten metal within said mold .and around ,the core containing said chill plates. vand ren'iov'ing the cast cylinder from .the 'mold and the core and chill plates .from the cylinder'. i

` 3. rlhe herein describedy method oit .pron d ucing castmetal engine cylinders, and the like consisting in forming a suitable core, embedding in the periphery o1 such core a plurality ot' segmental chill plates ot ununi- 'orm thickness througho-ut their extent to afford unequal chilling capacity, position-v ing saidcore in a suitable mold, and casting' the cylinder from molten metal Within said mold and around the core containing said chill plates, and removing the cast cylinder trom the mold and the core and chill plates from the cylinder.

4. The herein described method of producing cast metal jaclreted engine cylinder and the like, consisting in casting the cylinder from molten metal in a suitable mold and countcracting the heat retaining eifect` of the jacleted portion of the cylinder by proportionately chilling the cylinder casting troni the interior thereof in direct relation with the heat retaining etl'ect produced by the jacket, i

5. The hei-cin described method of producing cast metal engine cylinders and the like, consisting in casting such cylinder from molten metal in a suitable mold and subjecting the interior to a chilling influence ununilorm throughout the length of the cylinder.

(3. The herein described method ot producing jacketed cast metal engine cylinders and the like consisting in casting such cylinders from molten metal in a suitable mold and subjecting the jacketed portion ot the cylinder to an interior cooling influence greater than the remainder of the cylinder.

7. The herein described. method of producing cast metal engine cylinders and the like, consisting in casting such cylinders from molten metal in a suitable mold around a core ot lriable material having embedded therein to a depth substantially iiush with contiguous portions of the core a plurality of segmental chill plates.

S. A core tor cast metal cylinders comprising a body of friable material, and a lou plurality of non-interengaging segmental chill plates embedded in the peripheral surface thereof in spaced relation between which portions of the body of friable material extends in substantially Hush relation with the exterior faces of the chill plate.

9. A core for cast metal cylinders comprising a body of friable material, and a plurality of non-interengaging segmental chill plates embedded in the peripheral surface thereof, the chill plates being separated one from another in approximate spaced relation to allow for shrinkage and interposed ridges of core material extending between said plate into substantially flush relation with the exterior faces thereof.

10. A core for cast metal cylinders comprising a body of friable material, and a plurality of segmental chill plates embedded in the peripheral surface thereof, said plates being of varying thickness throughout their length to afford ununiform chilling capacity.

l1. As an article ofmanufacture, a cast metal engine cylinder having a chill hardened interior surface, substantially as specitied.

12. As an article of manufacture, a cast metalengine cylinder having a surrounding water jacket,4 the interior of the cylinder being chill hardened to counteract the annealing effect of the surrounding Water jacket.

13. A chill plate for engine cylinder cores,

comprising a segmental arcuate plate of un` THOMAS P. GREENHOV.

Vitnesses Lne M. CHURCH, CARRIE L. HOWARD. 

